Configure the Yakult App MySQL Database

Yakult App uses MySQL as its primary data store. All sales orders, client records, products, user accounts, notifications, and generated reports are persisted in a single database named yakult_db. The backend is designed to manage its own schema — on every startup it inspects the database and applies any missing tables, columns, or indexes automatically. You only need to create the empty database and supply valid credentials; the rest is handled for you.

Requirements

MySQL 8.0+ (recommended) — older 5.7 installations may work but are not tested
Database name: yakult_db
A MySQL user with CREATE, ALTER, INDEX, INSERT, UPDATE, DELETE, and SELECT privileges on yakult_db

If you are setting up a local development environment on Windows, XAMPP is the easiest option. It bundles Apache, MySQL 8, and phpMyAdmin into a single installer with a one-click start panel — no manual MySQL configuration needed. Download it at apachefriends.org.

Setup

Install and start MySQL

Choose the installation method that best fits your environment.Option A — XAMPP (Windows, zero-config):

Download and install XAMPP from apachefriends.org.
Open the XAMPP Control Panel and click Start next to MySQL.
MySQL is now running on 127.0.0.1:3306 with user root and no password.

Option B — Standalone MySQL Server: Follow the official installation guide at dev.mysql.com/downloads/mysql for your operating system, then start the service.

Create the database

Connect to your MySQL server with a client of your choice (MySQL CLI, phpMyAdmin, MySQL Workbench, or DBeaver) and run:

CREATE DATABASE IF NOT EXISTS yakult_db;
USE yakult_db;

That is all that is required. The backend will create and maintain all tables automatically when it starts.

(Optional) Import the seed file

A seed SQL file is included in the repository at backend/database/yakult_db.sql. It contains the full CREATE TABLE statements and a small set of sample productos records that are useful for development and testing.

mysql -u root yakult_db < backend/database/yakult_db.sql

If your MySQL user has a password, add the -p flag:

mysql -u root -p yakult_db < backend/database/yakult_db.sql

This step is optional — the auto-migration on server startup will create all tables even without running the seed file. Import it only if you want pre-populated sample product data.

Update the backend connection config

Open backend/db.js and set the credentials to match your MySQL installation.

const mysql = require('mysql2/promise');

const pool = mysql.createPool({
  host: '127.0.0.1',    // MySQL host — use 127.0.0.1, not 'localhost' (see note below)
  port: 3306,            // MySQL port (default: 3306)
  user: 'root',          // Your MySQL username
  password: '',          // Your MySQL password
  database: 'yakult_db', // Must match the database you created above
  waitForConnections: true,
  connectTimeout: 10000, // ms to wait before throwing a connection error
});

module.exports = pool;

On Windows, using 'localhost' as the host can cause MySQL to attempt an IPv6 connection (::1) before falling back to IPv4, which sometimes results in an ETIMEDOUT error even when the server is running. Using '127.0.0.1' explicitly forces an IPv4 TCP connection and avoids this issue.

The default configuration uses an empty password for the root user. This is acceptable for local-only development but must never be used in any internet-facing or shared environment. Set a strong MySQL root password — or create a dedicated application user with limited privileges — before deploying to staging or production.

Start the backend and verify auto-migration

Start the backend server as described in the Backend Setup guide.

cd backend && npm run dev

On startup you will see the schema migration run before the server begins listening:

Servidor corriendo en http://localhost:3000

If there are any connection problems, the process will exit and print a descriptive error:

No se pudo preparar la base de datos: Error: connect ECONNREFUSED 127.0.0.1:3306

Double-check that MySQL is running and that the credentials in db.js are correct.

Auto-migration system

The backend includes a schema management module at backend/schema.js that runs the ensureSchema() function on every startup. You do not need to run any manual migration commands — the server maintains its own database structure. ensureSchema() performs the following operations each time the server starts:

Creates missing tables — if a table does not exist, it is created with its full column and constraint definitions
Adds missing columns — if a table exists but is missing a column (e.g. after a code update), the column is added with ALTER TABLE ... ADD COLUMN
Creates missing indexes — any indexes defined in the schema that are absent from the live table are created
Never destructive — no existing tables, columns, rows, or indexes are ever dropped or modified; all operations are additive only

Because every operation is idempotent, it is completely safe to restart the server as many times as needed.

Managed tables

The following 7 tables are created and maintained by ensureSchema():

Table	Description
`productos`	Yakult product catalogue (SKUs, names, prices)
`clientes`	Customer / distributor client records
`usuarios`	Application user accounts and roles
`ordenes`	Sales order headers (client, date, status, totals)
`orden_items`	Line items belonging to each order (product, qty, price)
`notificaciones`	In-app notifications for users
`reportes_ventas`	Persisted sales report snapshots

Connection pool reference

The mysql2/promise pool in db.js is shared across the entire application. Key configuration options:

Option	Value	Description
`host`	`127.0.0.1`	MySQL server address
`port`	`3306`	MySQL server port
`user`	`root`	MySQL username
`password`	“	MySQL password (empty by default)
`database`	`yakult_db`	Target database name
`waitForConnections`	`true`	Queue requests when all connections are busy, rather than throwing immediately
`connectTimeout`	`10000`	Milliseconds to wait for a new connection before raising an error

Setup

Documentation Index

​Requirements

​Setup

​Auto-migration system

​Managed tables

​Connection pool reference

Build docs developers (and LLMs) love

Requirements

Setup

Auto-migration system

Managed tables

Connection pool reference